Although Positron Emission Tomography (PET) has demonstrated unique capabilities in the noninvasive study of fundamental metabolic and physical processes, its widespread use is limited by the complexity of the procedures and the cost of the instrumentation. Particularly limiting has been the onsite accelerator required to produce the short-lived isotopes 'IC, 'IN, 150, and 'IF (CNOF), which are key to PET's power. A uniquely small 8 MeV cyclotron has been developed as a potential solution to this problem. Its size, weight, and configuration for minimizing shielding volume suggest that this cyclotron might be incorporated into a mobile radioisotope delivery system (MRDS). Such a system will permit sharing annual operating cost among several institutions in proportion to their usage and thus provide the lowest possible cost of providing CNOF for PET. Unfortunately, the cyclotron gains its advantage in size and simplicity by using several nuclear reactions for CNOF production that are not standard practice. As a result, there is a controversy over the question of whether this innovative but nonstandard approach has sufficient use to justify replacing the established technology. Consequently, a program to demonstrate the clinical utility of the 8 MeV proton cyclotron is a prerequisite to obtaining the private financing to develop and market a commercially available MRDS. In Phase I, quantitative goals for the Phase II demonstration will be developed: design and costing studies of the MRDS will be performed, and a study of the technical, legal, and economic feasibility of the MRDS will be undertaken. Anticipated Results/Potential Commercial Applications as described by the awardee: If the Phase II demonstration is successful, a major cost reduction in providing PET diagnostics procedures will be possible with the Phase III commercial product. The ability to share the MRDS also will permit institutions to have a PET facility better matched to their needs while time-sharing the annual fixed operating costs. If clinical utility cannot be demonstrated, the unit can provide a flexible research support facility that could be redeployed as programs change.